Disclosed herein is a method for preparing a hydrogel microparticle composition. A dispersion including 1 part by weight of N-isopropyl acrylamide, about 0.1-0.5 part by weight of chitosan, about 0-0.05 part by weight of N,N′-methylene bisacrylamide, about 0.1-0.5 part by weight of glacial acetic acid, and about 20-40 parts by weight of water is prepared. About 0.01-0.3 part by weight of an anionic initiator is added into the dispersion and the dispersion is allowed to undergo a polymerization reaction at a temperature of about 10-100° C. for about 1 to 5 hours, thereby producing a plurality of hydrogel microparticles dispersed in the water to form the hydrogel microparticle composition.